Rick Santorum
Rick Santorum is looking to replace Newt Gingrich as the "anti-Romney" candidate, and he has his chance to do so tonight in Colorado, Minnesota and Missouri. Reuters

The polls have opened for the Missouri 2012 Republican primary, but only three candidates will participate: Mitt Romney, Ron Paul and Rick Santorum.

Because of a combination of money struggles and in-party disputes, Missouri will hold both a primary and a caucus this year, and only the caucus will determine any delegates.

As a result, Newt Gingrich has announced his conscious decision not to participate, and news sources have dubbed it a meaningless primary more akin to a beauty contest than a legitimate race.

Nonetheless, Missouri voters are still expected to show up, and certainly they will see which candidates are still courting their votes. And Rick Santorum, a no-show in the polls since the Iowa caucus, may be able to secure his first official win by playing the game.

Last-minute polls have the former Pennsylvania senator leading the pack with 45 percent of voters' support, Mitt Romney trailing Santorum at 32 percent, and Ron Paul at 19 percent. If Santorum wins the Missouri primary, his chances of winning its delegates at the March 17 caucus are greatly increased. Newt Gingrich's snub, meanwhile, could end up hurting him when the former speaker looks to court the Southern GOP vote.

For those wanting to see how the Missouri 2012 GOP primary will pan out, and how the candidates will react to Santorum's likely win, you can check in on the results live by following our guide below.

When to Watch

Missouri polls will close at 7 p.m. CST (8 p.m. EST) tonight. The first results are expected around 8:30 p.m. EST. There will be no exit polls for the Missouri 2012 Republican primary.

Where to Watch

CNN will be host live coverage of the Missouri primary results from each of the three candidates' headquarters.

Where to Get Live Updates

The Washington Post and The Huffington Post will both host live blogs of the Missouri primary, while Fox News will post live updates on its official blog page throughout the night.

POLITICO and Google will also follow the Missouri 2012 Republican primary, and they will provide minute-by-minute live updates of what counties are reporting and who is currently in the lead.

How to Follow the Primary on Social Media

Use #MOPrimary to join the conversation about Tuesday's election on Twitter. Follow tweets from reporters covering the GOP event by subscribing to this list.